Comparing the effects of magnesium sulphate and remifentanil on the hemodynamic responses after laryngoscopy and endotracheal intubation

The sympathetic component of the autonomic nervous system is activated as a response to laryngoscopy and endotracheal intubation causing an increase in blood pressure and heart rate. In patients with underlying cardiovascular disease these changes may cause acute cardiac ischemia accompanying significant morbidity and mortality. The purpose of this current study was to compare the effects of magnesium sulphate and remifentanil on hemodynamic responses following laryngoscopy and endotracheal intubation.

In this double blind clinical trial 90 patients 15-50 years old, ASA I-II, who underwent elective surgery were randomly assigned into three groups, control, remifentanil and magnesium sulphate. Group 1, the control group. Group 2: Patients received magnesium sulphate 0.1 g/kg IV thirty minutes before laryngoscopy and endotracheal intubation. Group 3: Patients received remifentanil 1μg/Kg IV two minutes before laryngoscopy and endotracheal intubation. Blood pressure and heart rate were recorded before induction of anaesthesia, and at one, three and five minutes following laryngoscopy and intubation.

Mean changes of systolic and diastolic blood pressure, and heart rate one and three minutes following laryngoscopy and intubation in the magnesium sulphate group and remifentanil group were significantly different from the control group. (P< 0.05)

According to this study, the use of remifentanil and magnesium sulphate as premedication drugs before laryngoscopy and endotracheal intubation may effectively prevent rise of systolic and diastolic blood pressures and heartrate. Magnesium sulphate premedication did not control the hemodynamic parameters as effectively as remifentanil did; therefore we suggest using remifentanil as a premedication of choice in laryngoscopy and intubation.